transmission/libtransmission/tr-utp.cc

181 lines
4.3 KiB
C++

// This file Copyright © 2010 Juliusz Chroboczek.
// It may be used under the MIT (SPDX: MIT) license.
// License text can be found in the licenses/ folder.
#include <cstdint>
#include <string_view>
#include <event2/event.h>
#include <fmt/core.h>
#include <fmt/format.h>
#include <libutp/utp.h>
#include "transmission.h"
#include "crypto-utils.h" /* tr_rand_int_weak() */
#include "log.h"
#include "net.h"
#include "peer-mgr.h"
#include "peer-socket.h"
#include "session.h"
#include "tr-utp.h"
#include "utils.h"
#ifndef WITH_UTP
void UTP_Close(struct UTPSocket* socket)
{
tr_logAddTrace(fmt::format("UTP_Close({}) was called.", fmt::ptr(socket)));
}
void UTP_RBDrained(struct UTPSocket* socket)
{
tr_logAddTrace(fmt::format("UTP_RBDrained({}) was called.", fmt::ptr(socket)));
}
bool UTP_Write(struct UTPSocket* socket, size_t count)
{
tr_logAddTrace(fmt::format("UTP_Write({}, {}) was called.", fmt::ptr(socket), count));
return false;
}
bool tr_utpPacket(
unsigned char const* /*buf*/,
size_t /*buflen*/,
sockaddr const* /*from*/,
socklen_t /*fromlen*/,
tr_session* /*ss*/)
{
return false;
}
struct UTPSocket* UTP_Create(
SendToProc* /*send_to_proc*/,
void* /*send_to_userdata*/,
sockaddr const* /*addr*/,
socklen_t /*addrlen*/)
{
errno = ENOSYS;
return nullptr;
}
void tr_utpClose(tr_session* /*ss*/)
{
}
void tr_utpSendTo(
void* /*closure*/,
unsigned char const* /*buf*/,
size_t /*buflen*/,
struct sockaddr const* /*to*/,
socklen_t /*tolen*/)
{
}
#else
/* Greg says 50ms works for them. */
static auto constexpr UtpIntervalUs = int{ 50000 };
static void incoming(void* vsession, struct UTPSocket* s)
{
auto* session = static_cast<tr_session*>(vsession);
struct sockaddr_storage from_storage;
auto* const from = (struct sockaddr*)&from_storage;
socklen_t fromlen = sizeof(from_storage);
tr_address addr;
tr_port port = 0;
if (!tr_sessionIsUTPEnabled(session))
{
UTP_Close(s);
return;
}
UTP_GetPeerName(s, from, &fromlen);
if (!tr_address_from_sockaddr_storage(&addr, &port, &from_storage))
{
tr_logAddWarn(_("Unknown socket family"));
UTP_Close(s);
return;
}
tr_peerMgrAddIncoming(session->peerMgr, &addr, port, tr_peer_socket_utp_create(s));
}
void tr_utpSendTo(void* closure, unsigned char const* buf, size_t buflen, struct sockaddr const* to, socklen_t tolen)
{
auto const* const ss = static_cast<tr_session const*>(closure);
if (to->sa_family == AF_INET && ss->udp_socket != TR_BAD_SOCKET)
{
(void)sendto(ss->udp_socket, reinterpret_cast<char const*>(buf), buflen, 0, to, tolen);
}
else if (to->sa_family == AF_INET6 && ss->udp6_socket != TR_BAD_SOCKET)
{
(void)sendto(ss->udp6_socket, reinterpret_cast<char const*>(buf), buflen, 0, to, tolen);
}
}
static void reset_timer(tr_session* ss)
{
int sec = 0;
int usec = 0;
if (tr_sessionIsUTPEnabled(ss))
{
sec = 0;
usec = UtpIntervalUs / 2 + tr_rand_int_weak(UtpIntervalUs);
}
else
{
/* If somebody has disabled uTP, then we still want to run
UTP_CheckTimeouts, in order to let closed sockets finish
gracefully and so on. However, since we're not particularly
interested in that happening in a timely manner, we might as
well use a large timeout. */
sec = 2;
usec = tr_rand_int_weak(1000000);
}
tr_timerAdd(ss->utp_timer, sec, usec);
}
static void timer_callback(evutil_socket_t /*s*/, short /*type*/, void* vsession)
{
auto* session = static_cast<tr_session*>(vsession);
UTP_CheckTimeouts();
reset_timer(session);
}
bool tr_utpPacket(unsigned char const* buf, size_t buflen, struct sockaddr const* from, socklen_t fromlen, tr_session* ss)
{
if (!ss->isClosed && ss->utp_timer == nullptr)
{
ss->utp_timer = evtimer_new(ss->event_base, timer_callback, ss);
if (ss->utp_timer == nullptr)
{
return false;
}
reset_timer(ss);
}
return UTP_IsIncomingUTP(incoming, tr_utpSendTo, ss, buf, buflen, from, fromlen);
}
void tr_utpClose(tr_session* session)
{
if (session->utp_timer != nullptr)
{
evtimer_del(session->utp_timer);
session->utp_timer = nullptr;
}
}
#endif /* #ifndef WITH_UTP ... else */